This invention relates to an apparatus for wrenching or torquing a threaded member of a movable device. More particularly, the wrenching apparatus is a power tool for loosening threaded nipples attached to meters.
Power tools to apply wrenching to threaded nuts and bolts have been disclosed in U.S. Pat. Nos. 3,955,447 and 4,027,560 to Parker and U.S. Pat. No. 3,706,244 to Wilmeth. These tools are used on devices that have a series of bolts and nuts; each tool uses one nut to provide the reaction force while wrenching is applied to another nut.
Wilmeth also shows in U.S. Pat. No. 4,309,923 a power tool for torquing a threaded connector mounted on a fixed pipe. In this case, the reaction force to the wrenching action on the connector is provided by a reaction foot that abuts the floor below the stationary pipe.
The prior art has not addressed the problem of loosening a threaded nipple from a meter after it has been disconnected for reconditioning and calibration. After years of service, the sealing compound used on the threads of the nipple sets so hard that it takes a torque in the range of 1000 to 2000 pound-feet to loosen a 3- or 4-inch nipple. Inasmuch as meters are made in different shapes and sizes, it is a difficult problem to hold the meter while such a large torque is applied to the nipple. A simple and practical structure for restraining meters of different configurations has not been found.
It is therefore a principal object of this invention to provide a wrenching tool that receives its reaction force solely from the device to which the threaded member is attached.
Another important object is to provide a power tool that is easily fitted to meters and nipples of different sizes.
Other features and advantages of the invention will be apparent from the description which follows.